Nonlinear viscoelastic medium equivalence for stress wave propagation in a jointed rock mass

2012 ◽  
Vol 50 ◽  
pp. 11-18 ◽  
Author(s):  
L.F. Fan ◽  
G.W. Ma ◽  
J.C. Li
Keyword(s):  
Wave Propagation ◽  
Rock Mass ◽  
Stress Wave ◽  
Viscoelastic Medium ◽  
Jointed Rock ◽  
Jointed Rock Mass ◽  
Stress Wave Propagation ◽  
Nonlinear Viscoelastic ◽  
Nonlinear Viscoelastic Medium

Stress wave propagation across jointed rock mass under dynamic extension and its effect on dynamic response and supporting of underground opening

2021 ◽  
Vol 108 ◽  
pp. 103648
Author(s):  
Jianbo Zhu ◽  
Yashi Li ◽  
Qi Peng ◽  
Xifei Deng ◽  
Mingzhong Gao ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Rock Mass ◽  
Dynamic Response ◽  
Stress Wave ◽  
Jointed Rock ◽  
Jointed Rock Mass ◽  
Stress Wave Propagation ◽  
Underground Opening

scholarly journals A Numerical Simulation of Blasting Stress Wave Propagation in a Jointed Rock Mass under Initial Stresses

2021 ◽  
Vol 11 (17) ◽  
pp. 7873
Author(s):  
Qian Dong ◽  
Xinping Li ◽  
Yongsheng Jia ◽  
Jinshan Sun
Keyword(s):  
Wave Propagation ◽  
Rock Mass ◽  
Initial Stress ◽  
Stress Wave ◽  
Jointed Rock ◽  
Jointed Rock Mass ◽  
Stress Waves ◽  
Initial Stresses ◽  
Stress Wave Propagation ◽  
Rock Masses

The initial stresses have a strong effect on the mechanical behavior of underground rock masses, and the initial stressed rock masses are usually under strong dynamic disturbances such as blasting and earthquakes. The influence mechanism of a blasting excavation on underground rock masses can be revealed by studying the propagation of stress waves in them. In this paper, the improved Mohr-Coulomb elasto-plastic constitutive model of the intact rock considering the initial damage was first established and numerically implemented in Universal Distinct Element Code (UDEC) based on the variation of the experimental stress wave velocity in the initial stressed intact rock, and the feasibility of combining the established rock constitutive model and the BB (Bandis-Barton) model which characterizes the nonlinear deformation of the joints to simulate stress waves across jointed rock masses under initial stress was validated by comparing the numerical and model test results subsequently. Finally, further parameter studies were carried out through the UDEC to investigate the effect of the initial stress, angle, and number of joints on the transmission of the blasting stress wave in the jointed rock mass. The results showed that the initial stress significantly changed the propagation of the stress waves in the jointed rock mass. When the initial stress was small, the transmission coefficients of the stress waves in the jointed rock were vulnerable to be influenced by the variation of the angle and the number of joints, while the effect of the angle and the number of joints on the stress wave propagation gradually weakened as the initial stress increased.

scholarly journals Effects of Unidirectional In Situ Stress on Crack Propagation of a Jointed Rock Mass Subjected to Stress Wave

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Zhanfeng Fan ◽  
Jianhua Cai
Keyword(s):  
Wave Propagation ◽  
Rock Mass ◽  
Crack Propagation ◽  
Stress Wave ◽  
Large Scale ◽  
Jointed Rock ◽  
In Situ Stress ◽  
Jointed Rock Mass ◽  
Stress Wave Propagation

This paper proposes a large-scale experiment combined with multiple cement mortar blocks to simulate stress wave propagation across a jointed rock mass under unidirectional in situ stress. Two identical mortar block models with smooth, dry, and unfilled joints were poured. The stress waves in Model 1 and Model 2 were generated by an electric spark source and a blast-induced source, respectively. The effects of these two excitation sources on stress wave propagation were compared through crack propagation experiments. The experimental results show that the peak value of the transmitted strain wave decreases as the in situ stress increases. The unidirectional in situ stress has a certain inhibitory effect on the stress wave propagation. It also indicates that for Model 1 with the electric spark source, no cracks on the upper surface, but a Livingstone blasting crater at the bottom is generated. For Model 2 with the blast-induced source, cracks on the upper surface and a blasting crater at the bottom are produced. The results verify the similarity between the electric spark source and the explosive source. The two-dimensional finite element program (ANSYS/LS-DYNA) was applied to further simulate the crack propagation of a jointed rock mass under different in situ stresses. The results of numerical simulation verify that the in situ stress has a clear guiding effect on the crack propagation.

scholarly journals Model Test Study on Cylindrical Blasting Stress Wave Propagation across Jointed Rock Mass with Different Initial Stresses

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Qian Dong ◽  
XinPing Li ◽  
JunHong Huang
Keyword(s):  
Rock Mass ◽  
Transmission Coefficient ◽  
Stress Wave ◽  
Confining Pressure ◽  
Jointed Rock ◽  
Cylindrical Wave ◽  
Jointed Rock Mass ◽  
Initial Stresses ◽  
Stress Wave Propagation ◽  
Intact Rock Mass

In the drilling and blasting excavation of underground rock mass, the stress wave produced by the blasting holes usually propagates in the form of cylindrical wave, while the rock mass surrounding the underground engineering is initially subjected to the in situ stress. To explore the propagation and attenuation law of cylindrical stress wave in the in situ stressed rock mass, a model test of cylindrical blasting stress wave propagation across the intact and jointed rock mass under different initial stresses was carried out. First, the attenuation law of the cylindrical stress wave in the intact rock mass under different confining pressures is analysed, and then the influence of the confining pressure scales, the angle, and the number of joints on the propagation law of the cylindrical blast wave in the jointed rock mass is studied. The experimental results show that the physical attenuation of the cylindrical wave in the intact rock mass decreases and then increases as the confining pressure increases from zero. Under zero confining pressure, the transmission coefficient of the cylindrical wave in the jointed rock mass decreases with the increase of joint angle, and the transmission coefficient increases with the increase of the joint angle under confining pressure. As the confining pressure increases from zero, the transmission coefficient shows a trend of increasing firstly and then decreasing.

scholarly journals Stress Wave Propagation through Rock Joints Filled with Viscoelastic Medium Considering Different Water Contents

2020 ◽  
Vol 10 (14) ◽  
pp. 4797 ◽  
Author(s):  
Xiaolin Huang ◽  
Shengwen Qi ◽  
Bowen Zheng ◽  
Youshan Liu ◽  
Lei Xue ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Water Content ◽  
Seismic Response ◽  
Transmission Coefficient ◽  
Stress Wave ◽  
Viscoelastic Medium ◽  
Rock Joints ◽  
Stress Wave Propagation ◽  
Multiple Reflections ◽  
Joint Spacing

A rock mass often contains joints filled with a viscoelastic medium of which seismic response is significant to geophysical exploration and seismic engineering design. Using the propagator matrix method, an analytical model was established to characterize the seismic response of viscoelastic filled joints. Stress wave propagation through a single joint highly depended on the water content and thickness of the filling as well as the frequency and incident angle of the incident wave. The increase in the water content enhanced the viscosity (depicted by quality factor) of the filled joint, which could promote equivalent joint stiffness and energy dissipation with double effects on stress wave propagation. There existed multiple reflections when the stress wave propagated through a set of filled joints. The dimensionless joint spacing was the main controlling factor in the seismic response of the multiple filled joints. As it increased, the transmission coefficient first increased, then it decreased instead, and at last it basically kept invariant. The effect of multiple reflections was weakened by increasing the water content, which further influenced the variation of the transmission coefficient. The water content of the joint filling should be paid more attention in practical applications.

Combined Effect of Joint Contact Area and Temperature on Stress Wave Propagation in Granite Rock Mass

2020 ◽  
Vol 32 (12) ◽  
pp. 04020367
Author(s):  
Zhiliang Wang ◽  
Shuailong Jia ◽  
Nuocheng Tian ◽  
Feng Xiong ◽  
Zhitang Lu
Keyword(s):  
Wave Propagation ◽  
Rock Mass ◽  
Stress Wave ◽  
Contact Area ◽  
Combined Effect ◽  
Stress Wave Propagation ◽  
Granite Rock ◽  
Joint Contact
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